Search for: structural-transformation
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    A model-driven approach to semi-structured database design

    , Article Frontiers of Computer Science ; Volume 9, Issue 2 , 2015 , Pages 237-252 ; 20952228 (ISSN) Jahangard Rafsanjani, A ; Mirian Hosseinabadi, S ; Sharif University of Technology
    Higher Education Press  2015
    Recently XML has become a standard for data representation and the preferred method of encoding structured data for exchange over the Internet. Moreover it is frequently used as a logical format to store structured and semi-structured data in databases. We propose a model-driven and configurable approach for modeling hierarchical XML data using object role modeling (ORM) as a flat conceptual model. First a non-hierarchical conceptual schema of the problem domain is built using ORM and then different hierarchical views of the conceptual schema or parts of it are specified by the designer using transformation rules. A hierarchical modeling notation called H-ORM is proposed to show these... 

    Molecular dynamics investigation of β-SiC behavior under three-axial tensile loading

    , Article Journal of Computational and Theoretical Nanoscience ; Volume 8, Issue 11 , 2011 , Pages 2187-2192 ; 15461955 (ISSN) Mortazavi, B ; Simchi, A ; Besharati Givi, M. K ; Rajabpour, A ; Sharif University of Technology
    Molecular dynamics (MD) simulations were used to study the mechanical behaviour of β-SiC at nano-scale under tensile loading. Effects of loading rate and tensile temperature on the mechanical properties and failure were studied. Modified embedded-atom method (MEAM) potential and Berendsen thermostat were utilized for modelling. Periodic boundary conditions were employed and the behaviour of material was analyzed under three-axial loading condition at which the stress- strain relation was acceptably size independent. It is shown that with increasing the loading rate from 5 m/s to 70 m/s, the failure strain increases without a remarkable change in the stress-strain relationship. The MD... 

    Does knowledge base complexity affect spatial patterns of innovation? An empirical analysis in the upstream petroleum industry

    , Article Technological Forecasting and Social Change ; Volume 143 , 2019 , Pages 273-288 ; 00401625 (ISSN) Maleki, A ; Rosiello, A ; Sharif University of Technology
    Elsevier Inc  2019
    Using network analysis, we investigate if an industry's complex and integrated knowledge base leads to a higher spatial concentration (or dispersal)of innovative activities. This is important because the extant literature provides competing claims about how knowledge base complexity impacts on the spatial distribution of industrial innovation. To help empirically resolve this issue, we draw on longitudinal data (1970–2010)on the upstream petroleum industry and build indexes of entropy and complexity to render knowledge base dynamics, assess the spatial concentration of innovation, and study industry structural transformations. We first find a correlation – once a crucial distinction between... 

    Synthesis and characterization of highly hydrophilic self-associating terpolymers: Rheological, thermal, and corrosion protection studies

    , Article Chemical Engineering Journal ; Volume 405 , 2021 ; 13858947 (ISSN) Ghaderi, S ; Ramazani Saadatabadi , A ; Haddadi, S. A ; Sharif University of Technology
    Elsevier B.V  2021
    In this study, water-soluble terpolymers containing highly hydrophilic monomers of acrylamide and maleic anhydride and highly hydrophobic monomers of styrene were synthesized (ASM) through the one-step inverse emulsion polymerization. Proton nuclear magnetic resonance (1H NMR), fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction pattern (XRD) were performed to investigate the chemical structures and structural transformations of ASM. Thermal stability and thermal decomposition steps of ASM were studied by thermogravimetric analysis (TGA). An Ubbelhode capillary viscometer and a rheological mechanical spectrometer (RMS) were employed to obtain the specific, relative, and...